Abbreviation: S3
The finding of an extra heart sound on cardiac auscultation that occurs during early diastole, as the ventricle is filling. An S3 gallop is due to a sudden deceleration of blood flow from the left atrium into the left ventricle. Can be normal variant in young, healthy individuals, but can be also associated with congestive heart failure, dilated cardiomyopathy, and/or volume overload. Best heard with the bell of the stethoscope over the apex.